feat: assign issue or PR to project on setting milestone

[mfranzke]

No description provided.

[Copilot]

Pull Request Overview

This PR introduces a new GitHub Actions workflow that assigns issues or pull requests to a specific project when a milestone is set.

• Added a new workflow file to trigger on "milestoned" events for issues and pull requests.
• The workflow includes steps to check out code and assign the corresponding issue or PR to a project using the GitHub API.

Comments suppressed due to low confidence (1)

.github/workflows/99-assign-to-project-on-milestone-set.yml:19

• Ensure that the GitHub Actions expression correctly prioritizes the issue over the pull request because the use of '||' might not behave as intended in all scenarios; consider verifying or refactoring this logic.

          ISSUE_OR_PR=${{ github.event.issue || github.event.pull_request }}